Surya: Sun, solar, heating, right nostril
Chandra: moon, lunar, cooling, left nostril
Bhedana: clear, cleanse, free flowing
Perform this kumbhaka in order to clear the two principal nadis, ida and pingala, also known as the sun and moon, and also to cleanse the overall system of nadis throughout the body.
In this video David gives step by step instructions how to orient yourself in this pranayama.